1. Field of the Invention
The present invention relates to a semiconductor chip carrying adhesive tape/sheet, a semiconductor chip carrier and a semiconductor chip packaging body, to be used when mounting a semiconductor chip on a lead frame, or storing, transporting or automatically taking out the semiconductor chip before the mounting, and a method of producing the semiconductor chip carrier, a method of mounting the semiconductor chip and a method of packaging the semiconductor chip.
2. Description of the Related Art
When mounting a semiconductor chip on a lead frame, processes below are performed in the related art.
(1) Grinding a back surface of a semiconductor wafer to make the semiconductor wafer have a desired thickness.
(2) Sticking an adhesive sheet to the semiconductor wafer.
(3) Sticking a wafer dicing sheet in accordance with need to fix the semiconductor wafer to a ring frame.
(4) Dicing the semiconductor wafer by a dicer.
(5) Expanding the wafer dicing sheet in accordance with need to separate the semiconductor chips obtained by the dicing.
(6) Picking up the semiconductor chip attached with an adhesive agent.
(7) Mounting the adhesive agent attached semiconductor chip on a lead frame and adhering the semiconductor chip to the lead frame via an adhesive agent.
In the method of mounting a semiconductor chip by the above processes, however, defective semiconductor chips wherein cutouts and cracks, etc. occurred at the time of dicing are also stuck to the adhesive sheet. Therefore, the yield is low and the adhesive sheets are wastefully used. Particularly, when an adhesive agent of the adhesive sheet is conductive and, for example, a large amount of a precious metal such as Ag powders, is contained in the adhesive agent, it ends up in wasting very high costs.
The present invention was made in consideration with the above circumstances and has as an object thereof to provide a semiconductor chip carrying adhesive tape and sheet capable of improving an yield of adhesive agent attached chips and preventing wasteful use of an adhesive agent, a semiconductor chip carrier, a method of producing the same, a method of mounting the semiconductor chip, a semiconductor chip packaging body, and a method of packaging the semiconductor chip by using the semiconductor chip carrying adhesive tape or sheet.
To attain the above object, according to the present invention, there is provided a semiconductor chip carrying adhesive tape, wherein a plurality of adhesive agent portions for adhering a semiconductor chip are intermittently formed on a tape shaped base material in a longitudinal direction of the base material, in a substantially identical shape with that of the semiconductor chip to be adhered or a slightly larger shape than that of the semiconductor chip to be adhered, and an adhesive agent constituting the adhesive agent portions has gradable adhesiveness (claim 1).
The semiconductor carrying adhesive tape may be wound to be a wound body. In this case, a release film may be stuck on the surface of the semiconductor chip carrying adhesive tape.
The adhesive agent which has gradable adhesiveness may have a stage of exhibiting tackiness (removable adhesiveness) and a stage of exhibiting-adhesiveness (a so-called tacky adhesive agent), or may be those which do not exhibit any tackiness/adhesiveness in a normal state but exhibit gradable tackiness/adhesiveness by a heat, compression or other triggers. Thus the adhesive agent of the adhesive agent portion has such gradable adhesiveness, sticking to a semiconductor chip and temporary/actual adhesion to a lead frame can be efficiently performed.
In the above invention (claim 1), second adhesive agent portions for adhering a cover member (here, xe2x80x9cadheringxe2x80x9d includes concepts of sticking and affixing) may be adhered at both end portions of the tape shaped base material so as not to contact the adhesive agent portion for adhering the semiconductor chip (claim 2).
According to the present invention, there is provided a semiconductor chip carrying adhesive sheet, wherein a plurality of adhesive agent portions for adhering semiconductor chips are formed on a sheet shaped base material, in a substantially identical shape with that of the semiconductor chips to be adhered or a slightly larger shape than the semiconductor chips to be adhered, and an adhesive agent constituting the adhesive agent portions has gradable adhesiveness (claim 3).
According to the present invention, there is provided a semiconductor chip carrier, which can be obtained by sticking a semiconductor chip to the adhesive agent portion of the semiconductor chip carrying adhesive tape according to the above invention (claims 1 and 2) or to the adhesive agent portion of the semiconductor chip carrying adhesive sheet according to the above invention (claim 3) (claims 4 and 5).
According to the present invention, there is provided a first semiconductor chip packaging body, which can be obtainable by adhering the semiconductor chip carrier according to the above invention (claim 4) and a continuous cover member on which a plurality of chip housings are intermittently formed in the longitudinal direction so that the semiconductor chips on the semiconductor chip carrier are housed in the chip housings on the cover member (claim 8), and a second semiconductor chip packaging body, which can be obtainable by adhering the semiconductor chip carrier according to the above invention (claim 5) and a tray shaped cover member on which a plurality of chip housings are formed so that the semiconductor chips on the semiconductor chip carrier are housed in the chip housings on the cover member (claim 9). Note that xe2x80x9cadheringxe2x80x9d here includes concepts of sticking, affixing and fusion bonding.
When using the semiconductor chip carrying adhesive tape or the semiconductor chip carrying adhesive sheet according to the present invention, since only non-defective semiconductor chips can be stuck to the adhesive agent portion for adhering the semiconductor chip of the semiconductor chip carrying adhesive tape or the semiconductor chip carrying adhesive sheet, a yield of adhesive agent attached semiconductor chips which should be mounted on a lead frame can be improved and a wasteful use of an adhesive agent can be prevented. Particularly, when the adhesive agent portion contains a conductive material made of a precious metal, such as Ag powders, costs for the adhesive agent can be considerably reduced comparing the case of sticking the adhesive agent portion allover the semiconductor wafer.
Also, in the present invention, since the adhesive agent portion formed on the base material is formed in a substantially identical shape with that of a semiconductor chip to be adhered or a slightly larger shape than that of the semiconductor chip to be adhered, there is an advantage that cutting of the adhesive agent portion is not necessary.